Patent WO 99/29178, in the name of the current applicant, describes a stuffing/dosing machine of this type comprising a hopper like deposit containing a food material, that can be closed hermetically, wherein a vacuum has been created, and two stuffing cylinders, which operate alternatively, provided with corresponding pistons that perform a first section of their respective strokes directly within a narrowed area or antechamber in the lower part of the deposit in order to stir and push the food material as far as respective stuffing-dosing chambers placed at the base of said deposit and aligned coaxially with the cylinders, and a second section within said stuffing-dosing chambers to compact and introduce the food material into respective collector pipes connected to a rotary collector/distributor valve, the movement of which is synchronized with that of said stuffing cylinders to give way alternatively to the food material driven by one or other of the cylinders towards a common outlet duct. The speed and travel of the cylinder strokes and the movements of the valve are controlled by regulating means to provide a single continuous flow of food materials in said outlet conduit or, optionally, an interrupted flow of precisely dosed portions.
The said two stuffing cylinders are located outside the deposit, parallel to one another and in proximity, in a slightly inclined position and they are housed in an empty section of a side wall of the deposit, while their corresponding stems extend through the deposit wall to actuate in the antechamber and in the stuffing-dosing chambers located at the base of the deposit. In this way, the deposit, the antechamber, the cylinders, the pistons and the stuffing-dosing chambers form an ensemble or first structural unit, which is articulated at the base thereof with respect to the machine bed so that it can tilt, moving between a first position, or operative position, in which lower mouthpieces of the stuffing-dosing chambers are hermetically positioned in higher inlet mouthpieces of said alternative valve, and a second position, or cleaning and maintenance position, wherein said lower mouthpieces of the stuffing-dosing chambers are separated from said higher inlet mouthpieces of the alternative valve to a sufficient degree to enable easy access to both mouthpieces.
Patent U.S. Pat. No. 5,097,876, in the name of the current applicant, discloses a machine similar to that described above, but provided with a single cylinder having a single piston and dosing means associated with the outlet conduit.
Although these arrangements have proved to be satisfactory in practice, they can be improved, particularly when the material to be formed is, for example, meat cut into pieces or minced, that is compact and has high adherence properties, such as a meat mass for preparing mortadellas and salamis, and meat at a relatively low temperature, for example, between 0° C. and −5° C. In this case, the means for stirring and driving the material towards the inlet to the stuffing-dosing chambers, which consist of the pistons in the first section of their strokes, prove to be inefficient and the material tends to form gluts that prevent it from moving down inside the hopper.
An object of this invention is to provide one of said improvements concerning the accessibility to different parts of the machine, for example, to the piston heads, the stirring and driving means, stuffing-dosing chambers, valve, etc.
Another object of this invention is to provide another of said improvements concerning said means for stirring the food material contained in the deposit and driving it towards the antechamber where the first section of the stroke of the pistons is performed.